Particle-removing apparatus for a semiconductor device manufacturing apparatus and method of removing particles

ABSTRACT

In a semiconductor device manufacturing apparatus that processing a substrate by applying a voltage to a gas to create a plasma, positively charged particles are trapped or guided at the instant that the cathode voltage is stopped, by an electrode to which is imparted a negative voltage, so as to prevent particles reaching the substrate.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a particle-removing apparatusfor a semiconductor device manufacturing apparatus and to a method ofremoving particles, and more specifically it relates to aparticle-removing apparatus that prevents the falling of particles thatare generated during a process onto a wafer, and to a method forremoving particles.

[0003] 2. Description of the Related Art

[0004] Particles that are generated in the process of manufacturing asemiconductor device, and in particular in a process that makes use ofplasma, are a cause of reduced yield and a deterioration of uptime.These particles can be caused by the peeling off of substances that havebeen deposited within the process equipment by reactions and by growthof substances generated by reaction within the plasma. To prevent thefalling of these particles onto a substrate, as described in theJapanese Unexamined Patent Publications (KOKAI) No. 5-29272 and No.7-58033, there has been a proposal of an apparatus in which thesubstrate is covered after a process is completed.

[0005]FIG. 9(a) is a drawing that shows a plasma etching apparatus ofthe past, in which the reference numeral 2100 denotes a processingchamber, inside which are provided an upper processing electrode 2200and a lower processing electrode 2300, the upper processing electrode2200 being grounded, and a high-frequency power supply 2400 beingconnected to the lower processing electrode 2300.

[0006] Above the lower processing electrode 2300 there is provided anelectrostatic chuck electrode 2700, which is insulated by means of aninsulator 1900, a voltage being applied to this electrostatic chuckelectrode 2700 from a power supply 2600, so as to hold a semiconductorsubstrate 3000. The processing chamber 2100 is provided with an intakeport 3100 for processing gas and an exhaust port 3200. A cover 3600 isprovided so that particles do not fall onto the semiconductor substrate3000.

[0007]FIG. 9(b) illustrates the general equipment operation cycle of aplasma etching process in a semiconductor device manufacturing process.

[0008] This process is for the case of a cycle in which a singlesubstrate is processed. The substrate 3000, which is transported from atransporting port 3800, is transported to within the processing chamber2100, at which point the process gas is introduced from the process gasintake port 3100. When the pressure within the processing chamber 2100reaches a prescribed value, a high-frequency voltage is applied from thepower supply 2400, so as to generated a plasma that etches the substrate3000. Simultaneously with the above, the substrate 3000 is held by theelectrostatic chuck. After completion of the etching, the supply of thehigh-frequency voltage, the supply of the process gas, and theelectrostatic chuck are all stopped. After several seconds, an inert gasthat does not contribute to etching is supplied for a prescribed amountof time in order to quickly purge the chamber of the process gas. Thesubstrate 3000, after completion of this processing, is transported tooutside the processing chamber 2100 from the transporting port 3800.

[0009] In an apparatus of the past as described above, in order toprevent particles from falling onto the substrate 3000, the cover 3600is provided over the substrate 3000. According to an experiment by theinventor, however, in a semiconductor device manufacturing process thatuses plasma, the timing of the falling of particles onto a substrate wasshown to be intimately connected with the operating status of thesemiconductor device manufacturing apparatus. Specifically, in theabove-noted publications of the past, there was absolutely noconsideration given to the timing of the covering of the substrate, thisrepresenting a major problem with regard to not being able to preventthe attachment of particles to the substrate.

[0010] Accordingly, it is an object of the present invention to improveover the above-noted drawback in the prior art, in particular byproviding a novel particle-removing apparatus of a semiconductor devicemanufacturing apparatus and a method of removing particles whereby, bycontrolling the timing of the covering by a cover provided over thesubstrate in accordance with the processing condition of the substrate,the attachment of particles that are generated within the manufacturingapparatus during a process that uses plasma to the substrate isprevented.

[0011] It is another object of the present invention to provide novelparticle-removing apparatus of a semiconductor device particle andmethod of removing particles whereby, by making use of thecharacteristic that particles are positively charged, attachment of theparticles to the substrate is prevented without the use of a cover orthe like.

SUMMARY OF THE INVENTION

[0012] In order to achieve the above-noted object, the present inventionadopts the following basic technical constitution.

[0013] Specifically, a first aspect of a particle-removing apparatus ofa semiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in which a high-frequencyvoltage is applied between an upper electrode and a lower electrode soas to generate a plasma within a processing chamber that processes asubstrate located in the processing chamber, in which is provided acover that covers the substrate, the substrate being covered by closingthis cover, so as to prevent the attachment of particles within theprocessing chamber to the substrate, this particle-removing apparatusbeing provided with a first control means for controlling the timing ofthe drive of the above-noted cover, this control means performingcontrol so as to change the cover from the opened condition to theclosed condition immediately before stopping the application of thehigh-frequency voltage.

[0014] In a second aspect of a particle-removing apparatus according tothe present invention, control is performed so as to change theabove-noted cover from the closed condition to the opened condition insynchronization with a tranport operation of a substrate-transportingapparatus that is provided in the semiconductor device manufacturingapparatus.

[0015] In a third aspect of a particle-removing apparatus according tothe present invention, the timing of control of changing the cover fromthe closed condition to the opened condition is immediately beforetransporting the substrate after completion of processing to outside theprocessing chamber.

[0016] In a fourth aspect of a particle-removing apparatus according tothe present invention, the timing of control of changing the cover fromthe closed condition to the opened condition is immediately aftertransporting the substrate after completion of processing to outside theprocessing chamber.

[0017] In a fifth aspect of a particle-removing apparatus according tothe present invention, the timing of the control of changing the coverfrom the closed condition to the opened condition is immediately beforethe application of the high-frequency voltage.

[0018] In a sixth aspect of a particle-removing apparatus according tothe present invention, in addition to imparting a potential to theabove-noted cover, a second control means, for controlling the timing ofapplication of the potential to the cover, is provided, this secondcontrol means performing control so that the potential is imparted tothe cover minimally from immediately before the stopping of applicationof the high-frequency voltage to several seconds after the starting ofintroduction of a purging gas.

[0019] In a seventh aspect of a particle-removing apparatus according tothe present invention, the above-noted potential is imparted minimallyuntil immediately before the introduction of the purging gas.

[0020] In an eighth aspect of a particle-removing apparatus according tothe present invention, the above-noted potential is imparted until thetime at which the substrate is transported to outside the processingchamber.

[0021] In a ninth aspect of a particle-removing apparatus according tothe present invention, the above-noted potential either is equivalent toa self-bias potential that appears on the lower electrode of theprocessing electrodes or has the same polarity as and a larger absolutevalue than the above-noted self-bias potential.

[0022] In a tenth aspect of a particle-removing apparatus according tothe present invention, the above-noted potential is a potential that isequivalent to the potential on the lower electrode of the processingelectrodes.

[0023] A first aspect of a particle-removing method according to thepresent invention is a particle-removing method in a semiconductordevice manufacturing apparatus in which a high-frequency voltage isapplied between an upper electrode and a lower electrode so as togenerate a plasma within a processing chamber that processes a substratelocated in the processing chamber, in which is provided a cover thatcovers the substrate, the substrate being covered by closing this cover,so as to prevent the attachment of particles within the processingchamber to the substrate, this particle removing method performingcontrol so as to change the cover from the opened condition to theclosed condition immediately before stopping the application of thehigh-frequency voltage.

[0024] In a second aspect of a particle-removing method according to thepresent invention, control is performed so as to change the above-notedcover from the closed condition to the opened condition insynchronization with a transport operation of a substrate transportapparatus that is provided in the semiconductor device manufacturingapparatus.

[0025] A third aspect of a particle-removing method according to thepresent invention is a particle-removing method apparatus in asemiconductor device manufacturing apparatus in which a high-frequencyvoltage is applied between an upper electrode and a lower electrode soas to generate a plasma within a processing chamber that processes asubstrate located in the processing chamber, in which is provided acover that covers the substrate, the substrate being covered by closingthis cover, so as to prevent the attachment of particles within theprocessing chamber to the substrate, this particle-removing methodhaving a first step of changing the cover from the opened condition tothe closed condition, a second step of stopping the application of thehigh-frequency voltage immediately after the cover is placed in theclosed condition, and a third step of imparting a potential to theabove-noted cover.

[0026] An eleventh aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma thereof,thereby processing the substrate on the above-noted susceptor, thisparticle-removing apparatus being provided with a particle-removingelectrode for the purpose of removing particles inside the processingchamber, a negative voltage being applied to this particle-removingelectrode, thereby causing removal of charged particles in theprocessing chamber.

[0027] In a twelfth aspect of a particle-removing apparatus according tothe present invention, the above-noted particle-removing electrode isprovided between the upper electrode and the lower electrode.

[0028] In a thirteenth aspect of a particle-removing apparatus accordingto the present invention, an exhaust port is provided on a side wall ofthe etching processing chamber in the region in which theparticle-removing electrode is provided.

[0029] In a fourteenth aspect of a particle-removing apparatus accordingto the present invention, the particle-removing electrode is providedover the above-noted lower electrode, in a manner so as to surround thesubstrate.

[0030] In a fifteenth aspect of a particle-removing apparatus accordingto the present invention, the particle-removing electrode is providedbetween the processing electrodes and a processing chamber side wall.

[0031] In a sixteenth aspect of a particle-removing apparatus accordingto the present invention, the particle-removing electrode is anattachment-preventing plate that prevents attachment of sediments onto awall surface of the processing chamber.

[0032] In a seventeenth aspect of a particle-removing apparatusaccording to the present invention, the particle-removing electrode isprovided either within a gas intake or in the region of a gas exhaustport of the etching processing chamber.

[0033] An eighteenth aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, thisparticle-removing apparatus having a gas exhaust port of the processingchamber that is formed by an electrically conductive material, to whicha negative voltage is applied so as to remove charged particles fromwithin the processing chamber.

[0034] A nineteenth aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, thisparticle-removing apparatus being provided, between the upper electrodeand the lower electrode, with an electrically conductive grid-configuredmaterial for the purpose of removing particles, a negative voltage beingapplied to the grid-configured material, so as to remove chargedparticles from within the processing chamber.

[0035] A twentieth aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, thisparticle-removing apparatus being provided, in the region of substrate,with a particle-removing electrode for the purpose of removingparticles, a negative voltage having an absolute value that is greaterthan the self-bias voltage of the above-noted lower electrode beingapplied to this particle-removing electrode, so as to prevent thefalling of particles within the processing chamber onto the substrate.

[0036] A twenty-first aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, a prescribedbias being added to the voltage that is applied to the lower electrode,this being varied in the same manner as the self-bias voltage, therebycausing charged particles to be directed toward the lower electrode, soas to prevent these particles from falling onto the above-notedsubstrate.

[0037] In a twenty-second aspect of a particle-removing apparatusaccording to the present invention, a laser apparatus is provided forthe purpose of detecting the occurrence of the above-noted particles,light from this laser apparatus being shined in an area surrounding theabove-noted upper electrode so as to detect the presence of particlesinside the processing chamber, and a third control means being furtherprovided for the purpose of applying a negative voltage to theparticle-removing electrode, based on the results of this detection.

[0038] A twenth-third aspect of a particle-removing apparatus of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing apparatus in a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber and a prescribed voltage being applied to theabove-noted processing electrodes, so as to generate a plasma thereof,thereby processing the substrate on the above-noted susceptor, thisparticle-removing apparatus being provided with a electricallyconductive planar particle-removing electrode for the purpose ofremoving particles inside the processing chamber, a negative voltagebeing applied to this particle-removing electrode, thereby causingremoval of charged particles in the processing chamber.

[0039] In a twenty-fourth aspect of a particle-removing apparatusaccording to the present invention, the above-noted particle-removingelectrode is in the form of a grid configured electrically conductiveelectrode. In a twenty-fifth aspect of a particle-removing apparatusaccording to the present invention, the above-noted negative voltage isapplied after the completion of etching.

[0040] In a twenty-sixth aspect of a particle-removing apparatusaccording to the present invention, the above-noted negative voltage isapplied during transport of the substrate.

[0041] A fourth aspect of a particle-removing method of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing method for a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber, a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, and a particle-removingelectrode for the purpose of removing particles being provided insidethe processing chamber, whereby, after completion of the etching of thesubstrate, a negative voltage is applied to the particle-removingelectrode, so that charged particles inside the processing chamber areguided to this particle-removing electrode and caused to be attached tothe particle-removing electrode, thereby preventing the particles frombecoming attached to the substrate.

[0042] In a fifth aspect of a particle-removing method according to thepresent invention, after the application of the negative voltage to theparticle-removing electrode, the etching gas in the processing chamberis exhausted.

[0043] A sixth aspect of a particle-removing method of a semiconductordevice manufacturing apparatus according to the present invention is aparticle-removing method for a semiconductor device manufacturingapparatus that has an etching processing chamber, a pair of processingelectrodes formed by an upper electrode and a lower electrode, which areinstalled within the processing chamber, and a susceptor that holds asubstrate to be processed onto the top of the above-noted lowerelectrode, a processing gas being introduced into the etching processingchamber, and a prescribed voltage being applied to the above-notedprocessing electrodes, so as to generate a plasma of the gas, therebyprocessing the substrate on the susceptor, wherein a gas exhaust port ofthe processing chamber is formed of an electrically conductive material,and a negative voltage is applied to this exhaust port, so as to guidecharged particles toward the gas exhaust port and simultaneously exhaustthe etching gas from within the processing chamber.

[0044] An seventh aspect of a particle-removing method of asemiconductor device manufacturing apparatus according to the presentinvention is a particle-removing method for a semiconductor devicemanufacturing apparatus that has an etching processing chamber, a pairof processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within the processing chamber, and asusceptor that holds a substrate to be processed onto the top of theabove-noted lower electrode, a processing gas being introduced into theetching processing chamber, and a prescribed voltage being applied tothe above-noted processing electrodes, so as to generate a plasma of thegas, thereby processing the substrate on the susceptor, wherein bycausing the size of the generated plasma to greatly extend beyond thesubstrate, particles inside the processing chamber are caused to fallalong the periphery of the plasma, so that they are prevented frombecoming attached to the substrate.

[0045] A particle-removing apparatus for a semiconductor devicemanufacturing apparatus according to the present invention is aparticle-removing apparatus for a semiconductor device manufacturingapparatus in which a high-frequency voltage is applied between an upperelectrode and a lower electrode to cause a plasma within the processingchamber so as to process a substrate therewithin, a cover that coversthe substrate being provided, the substrate being covered by changingcover to the closed condition, so as to prevent particles within theprocessing chamber from becoming attached to the substrate, and a firstcontrol means that controls the timing of the drive timing of the coverbeing also provided, this first control means performing control so thatthe cover is changed from the opened condition to the closed conditionimmediately before stopping the application of the above-notedhigh-frequency voltage applied between an upper electrode and a lowerelectrode, and so that the cover is changed from the closed condition tothe opened condition in synchronization with a transporting operation ofa substrate transport apparatus provided in the semiconductor devicemanufacturing apparatus.

[0046] Therefore, by driving the cover so as to cover the substrateimmediately before particles are generated, the attachment of theparticles to the substrate is prevented.

[0047] Additionally, by imparting an appropriate potential to the cover,the cover has a dust-collecting action, enabling even more effectiveprevention of attachment of the particles to the substrate.

[0048] Next, yet another aspect of an embodiment of the presentinvention will be described.

[0049]FIG. 21 is a photograph of the behavior of particles in a plasma,inserted into a schematic representation of the apparatus. The rightedge of the drawing corresponds to the region at the center of theprocess apparatus, and the left edge corresponds to the region of thewall of the process apparatus.

[0050] Particles are trapped in a sheath region in proximity to theupper electrode as shown in FIG. 21 and, at the instant the plasmacollapses, so that the particles in the region of the upper electrodefly toward the outer walls by the potential of the afterglow plasma. Inthe center part of the chamber, however, the particles fall downwardaround the outside of the plasma, and in the region of the lowerelectrode, this being the region of the wafer, it can be seen that thenegative self-bias potential causes the particles to fly towards thewafer.

[0051] From the above-noted results, the particles are seen to bepositively charged, and the basis of the present invention is the use ofthis fact to remove the particles using electrostatic induction.

[0052]FIG. 9(b) shows an example of the relationship between the numberof particles that are generated in the etching apparatus duringoperation, and the operation condition of the apparatus at that time.

[0053] The apparatus that is shown in FIG. 9(a) is an etching apparatusof the past that has flat parallel processing electrodes.

[0054]FIG. 9(b) is a representation of a cycle of processing onesubstrate. When the substrate is transported to inside the processingchamber from the transporting port, the processing gas is supplied and,when the pressure within the processing chamber reaches a prescribedvalue, a high-frequency voltage is applied, so as to generate a plasma,thereby causing etching of the substrate. When this is done, thesubstrate is held by the susceptor on the top of the lower electrode.

[0055] After completion of the above-noted etching, the supply of thehigh-frequency voltage, the supply of the process gas, and theelectrostatic chucking are all stopped. After several seconds, an inertgas that does not contribute to etching is supplied for a prescribedamount of time in order to quickly purge the chamber of the process gas,this causing the pressure within the processing chamber to rise.

[0056] The substrate, after completion of this processing, istransported to outside the processing chamber from the transportingport. In the drawing, the number of particles P represented by theellipses is the result of introducing the light from a laser into theregion over the substrate in the processing chamber, and using a CCDcamera to photograph the light scattered by particles that traverse thislaser light, a signal that indicates the operating condition of theetching apparatus being simultaneously captured. The number shown is theaccumulated number obtained from the processing of 25 substrates.

[0057] From FIG. 9(b), it is clear that the occurrence of particles Pduring etching corresponds to the operating condition of the apparatus.That is, while there is almost no particle generation during etching,when the etching is completed, there is a time when a large number ofparticles are generated, and the frequency of generation of particles ishigh when the purging gas is introduced.

[0058] A detailed examination of the images obtained from the lightscattered by the particles revealed that the traces of particles at thetime of the completion of the etching exhibit a tendency to be directedtoward the substrate, and a tendency to be directed toward the exhaustport when the purging gas is introduced.

[0059] From the above, it can be envisioned that because thehigh-frequency power supply is stopped when the etching is completed,particles that float during etching fall and, because the viscous flowof the processing gas is small, the particles fly toward the substrate,on which all of its electrical charge have not been removed.

[0060] It is further envisioned, however, that several seconds after thecompletion of etching, purging gas is introduced, the result being thatthe particles head toward the exhaust port with the purging gas.

[0061] In the present invention, the wafer is covered when the supply ofvoltage is stopped. Also, using the fact that the particles in theprocessing chamber are positively charged, by imparting a negativepotential to an electrically conductive plate or grid, the generatedparticles are trapped, or caused to migrate toward the exhaust port,thereby preventing them from reaching the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0062]FIG. 1 is block diagrams that show a particle-removing apparatusof a semiconductor device manufacturing apparatus according to thepresent invention.

[0063]FIG. 2 is a drawing that shows the configuration of aparticle-removing apparatus according to the present invention.

[0064]FIG. 3 is a drawing that shows the operational timing of asubstrate cover in the first embodiment of the present invention.

[0065]FIG. 4 is a drawing that shows the operational timing of asubstrate cover in the second embodiment of the present invention.

[0066]FIG. 5 is a drawing that shows the operational timing of asubstrate cover in the third embodiment of the present invention.

[0067]FIG. 6 is a drawing that shows the timing of the application of apotential to the substrate cover in the fourth embodiment of the presentinvention.

[0068]FIG. 7 is a drawing that shows the timing of the application of apotential to the substrate cover in the fifth embodiment of the presentinvention.

[0069]FIG. 8 is a drawing that shows the timing of the application of apotential to the substrate cover in the sixth embodiment of the presentinvention.

[0070]FIG. 9(a) is a drawing that shows the configuration of an etchingapparatus of the past, and FIG. 9(b) is a drawing that shows therelationship between the operating condition of an etching apparatus andthe number of particles generated.

[0071]FIG. 10 is a drawing that shows the operational timing in aconventional etching apparatus.

[0072]FIG. 11 is drawing that shows the seventh embodiment of thepresent invention.

[0073]FIG. 12 is drawing that shows the eight embodiment of the presentinvention.

[0074]FIG. 13 is drawing that shows the ninth embodiment of the presentinvention.

[0075]FIG. 14 is drawing that shows the tenth embodiment of the presentinvention.

[0076]FIG. 15 is drawing that shows the eleventh embodiment of thepresent invention.

[0077]FIG. 16 is drawing that shows the twelfth embodiment of thepresent invention.

[0078]FIG. 17 is drawing that shows the thirteenth embodiment of thepresent invention.

[0079]FIG. 18 is drawing that shows the fourteenth embodiment of thepresent invention.

[0080]FIG. 19 is drawing that shows the fifteenth embodiment of thepresent invention.

[0081]FIG. 20 is drawing that shows the sixteenth embodiment of thepresent invention.

[0082]FIG. 21 is a photograph that show the movement of particles in aplasma.

[0083]FIG. 22 is a drawing that shows the operational timing of asubstrate cover in the seventeenth embodiment of the present invention.

[0084]FIG. 23 is a drawing that shows the operational timing of asubstrate cover in the eighteenth embodiment of the present invention.

[0085]FIG. 24 is a drawing that shows the operational timing of asubstrate cover in the nineteenth embodiment of the present invention.

[0086]FIG. 25 is a drawing that shows the timing of the application of apotential to the substrate cover in the twentieth embodiment of thepresent invention.

[0087]FIG. 26 is a drawing that shows the timing of the application of apotential to the substrate cover in the twenty-first embodiment of thepresent invention.

[0088]FIG. 27 is a drawing that shows the timing of the application of apotential to the substrate cover in the twenty-second embodiment of thepresent invention.

[0089]FIG. 28 is a cross-sectional view that shows the structure of ageneral DC plasma processing apparatus.

[0090]FIG. 29 is a drawing that shows the twenty-third embodiment of thepresent invention.

[0091]FIG. 30 is a drawing that shows the twenty-fourth embodiment ofthe present invention.

[0092]FIG. 31 is a drawing that shows the twenty-fifth embodiment of thepresent invention.

[0093]FIG. 32 is a drawing that shows the twenty-sixth embodiment of thepresent invention.

[0094]FIG. 33 is a drawing that shows the twenty-seventh embodiment ofthe present invention.

[0095]FIG. 34 is a drawing that shows the twenty-eight embodiment of thepresent invention.

[0096]FIG. 35 is a drawing that shows the twenty-ninth embodiment of thepresent invention.

[0097]FIG. 36 is a drawing that shows the thirtieth embodiment of thepresent invention.

[0098]FIG. 37 is a drawing that shows the thirty-first embodiment of thepresent invention.

[0099]FIG. 38 is a drawing that shows the thirty-second embodiment ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0100] Embodiments of the present invention are described below indetail, with reference being made to the relevant accompanying drawings.

[0101]FIG. 1(a) is a block diagram that show the structure of anembodiment of the present invention, this being a semiconductor devicemanufacturing apparatus.

[0102] This block diagrams shows a semiconductor device manufacturingapparatus 4000 in which a high-frequency voltage is applied between anupper electrode 2200 and a lower electrode 2300, so as to generate aplasma inside a processing chamber 3100, thereby processing a substrate3000, a cover 3600 being provided which covers the substrate, this cover3600 being closed to cover the substrate 3000, thereby preventing theattachment of particles to the substrate 3000.

[0103] In the above-noted apparatus, there is provided a first controlmeans 200, which controls the drive timing of the cover 3600, thiscontrol means 200 performing control so that the cover is changed fromthe opened condition to the closed condition immediately before stoppingthe application of the high-frequency voltage, and also performingcontrol so that the cover 3600 is changed from the closed condition tothe opened condition in synchronization with a transport operation of asubstrate transport apparatus 1600, which is provided in thesemiconductor device manufacturing apparatus 4000.

[0104]FIG. 1(b) is a block diagram that shows the overall configurationa plasma etching apparatus according to the present invention, thisbeing formed by a driving apparatus 400 for the cover 3600, an etchinggas supply apparatus 1200 for supplying etching gas to inside theprocessing chamber 2100, a purging gas supply apparatus 1300 forsupplying purging gas to inside the processing chamber so as to exhaustthe etching gas therefrom, a vacuum adjustment apparatus 1400 for thepurpose of adjusting the degree of vacuum inside the processing chamber,an exhausting apparatus 1500 for exhausting the gas from within theprocessing chamber, a substrate transporting apparatus 1600 fortransporting the substrate, a high-frequency (less than 10 GHz) powersupply 2400 for generating a plasma, and a controller 1700, a DC powersupply 2600 for the electrostatic chuck that holds the substrate,controller 1700, such as a microcomputer or sequencer or the like, whichcontrols a driving apparatus 400, an etching gas supply apparatus 1200,a purging gas supply apparatus 1300, a vacuum adjustment apparatus 1400,an exhausting apparatus 1500, a substrate transporting apparatus 1600, ahigh-frequency power supply 2400, and the configuration being such thatthe substrate 3000 is subjected to the prescribed processing.

[0105] In the above-noted apparatus 4000, the first control means 200and a second control means 300 are included within the controller 1700.Thus, the semiconductor device manufacturing apparatus used in thepresent invention, with the exception of the control of the cover 3600,has the same configuration as in the past.

[0106]FIG. 9(b) is a drawing that shows the relationship between thenumber of particles P that are generated during plasma etching and theoperating condition of the etching apparatus.

[0107] In this drawing, the number of particles P that are representedby the ellipses is the result of introducing the light from a laser intothe region over the substrate in the processing chamber, and using a CCDcamera to photograph the light scattered by particles that traverse thislaser light, a signal that indicates the operating condition of theetching apparatus being simultaneously captured, this number being theaccumulated value obtained by processing 25 substrates. The generationof particles P during etching has a clear relationship to the operatingcondition of the apparatus. That is, while there is almost no particlegeneration during etching, when the etching is completed, there is atime when a large number of particles are generated, and the frequencyof generation of particles is high when the purging gas is introduced.

[0108] If a detailed examination is made of the images obtained from thelight scattered by the particles, it is seen that the traces ofparticles at the time of the completion of the etching exhibit atendency to be directed toward the substrate, and a tendency to bedirected toward the exhaust port when the purging gas is introduced.

[0109] From the above, it can be envisioned that because thehigh-frequency power supply is stopped when the etching is completed,particles that float during etching fall and, because the viscous flowof the processing gas is small, the particles fly toward the substrate,on which all of its electrical charge have not been removed. It isfurther envisioned, however, that several seconds after the completionof etching, purging gas is introduced, the result being that theparticles head toward the exhaust port with the purging gas.

[0110] The embodiments of the present invention to be described belowwere invented with the above-noted phenomenon as a basis.

[0111] The first to sixteenth embodiments of the present inventiondescribed below all can be applied to an RF plasma CVD apparatus, an RFplasma etching apparatus, and an RF plasma sputtering apparatus. Unlessspecifically indicated, the descriptions of the embodiments will be forthe case of application to an RF plasma etching apparatus. However, itshall be understood that these embodiments can be applied as well to theabove-noted other types of RF processing apparatuses.

[0112] (First Embodiment)

[0113] The flow of cover operation timing in the first embodiment of thepresent invention is shown in FIG. 3(a). At the time t1, immediatelybefore the stopping of the high-frequency voltage, the cover 3600 thatcovers the substrate 3000 is closed and, at the instant that thehigh-frequency voltage is stopped, particles that fall toward thesubstrate 3000 are caught by the cover 3600. The cover 3600 remainsclosed during the introduction of the purging gas, at which time thereis a high frequency of generation of particles and, after theintroduction of the purging gas is stopped, at the time t2, immediatelybefore the processed substrate is transported to outside the processingchamber 2100, the cover is opened. Thus, during the period of time whenmany particles P would fall onto the substrate, because the cover 3600is in the closed condition, thereby reliably covering the substrate3000, the attachment of the particles onto the substrate 3000 isprevented.

[0114] The shape of the cover can be that of a single sheet, or that ofa plurality of blades, such as those of a camera shutter. In contrast tothe prior art, the present invention is not limited in application to aplasma etching apparatus, and can be applied as well to otherapparatuses, such as a plasma CVD apparatus, which uses plasma toperform processing.

[0115] As shown in FIG. 3(b), the timing of the opening of the cover canbe established at time t21, which is immediately after the transport ofthe processed substrate to outside the processing chamber 2100.

[0116] (Second Embodiment)

[0117] The flow of cover operation timing in the second embodiment ofthe present invention is shown in FIG. 4. At the time t1, immediatelybefore the stopping of the high-frequency voltage, the cover 3600 thatcovers the substrate 3000 is closed and, at the instant that thehigh-frequency voltage is stopped, particles that fall toward thesubstrate 3000 are caught by the cover 3600. After the processedsubstrate 3000 is transported to outside the processing chamber 2100, atthe time t3, immediately before the next substrate is transported intothe processing chamber, the cover 3600 is opened. Thus, by operating thecover 3600 in this manner, attachment of particles that fall onto thesubstrate is prevented.

[0118] (Third Embodiment)

[0119] The flow of cover operation timing in the third embodiment of thepresent invention is shown in FIG. 5. At the time t4, immediately beforethe application of the high-frequency voltage, the cover 3600 thatcovers the substrate 3000 is opened and, at time t1, immediately beforethe high-frequency voltage is stopped, the cover is closed. By closingthe cover when etching is not being performed, particles occurringbecause of peeling from the upper electrode 2200 or from the insidewalls of the processing chamber 2000 are caught by the cover, therebypreventing the attachment of these particles to the substrate.

[0120] Furthermore, in addition to the above-noted configurations, it ispossible to use a configuration in which a detection means is providedthat detects that the cover has been placed in the closed condition, theresult of the detection by this detection means being used to turn offthe high-frequency power supply 2400.

[0121] (Fourth Embodiment)

[0122] The flow of cover operation timing in the fourth embodiment ofthe present invention is shown in FIG. 6(a). In addition to the first tothe third embodiments, during the period of time from t5, immediatelybefore the stopping of the application of the high-frequency voltage, tothe time t6, several seconds after the start of the introduction of thepurging gas, a potential is imparted to the cover 3600. Because evenimmediately after the stopping of the application of the high-frequencyvoltage, particles fall toward the charged substrate that has a residualcharge from the electrostatic chuck, this cover potential can beselected as a value that is either equivalent to the self-bias potentialof the lower electrode 2300, or as a potential with the same polarity asand a larger absolute value than the above-noted self-bias potential.Particles that are generated immediately after the stopping ofapplication of the high-frequency voltage fall toward the cover and areattracted to the cover 3600. Particles that are generated after theintroduction of the purging gas follow the flow of the purging gas, andfall toward the exhaust port, so that they do not become attached to thesubstrate.

[0123] The material of the cover 3600 can be the same conductivematerial as the processing chamber 2100 inner wall, this being forexample an aluminum alloy and, to reduce the number of particles thatare generated, it can also have a metallic surface that is covered withaluminum oxide or silicon oxide.

[0124] It is also possible, as shown in FIG. 6(b), to impart thepotential at time t61, immediately before the introduction of thepurging gas.

[0125] (Fifth Embodiment)

[0126] The flow of cover operation timing in the fifth embodiment of thepresent invention is shown in FIG. 7.

[0127] In the cases of the second and third embodiments of the presentinvention, as shown in FIG. 4 and FIG. 5, it is possible to impart apotential to the cover from the time t7, at which the application of thehigh-frequency voltage is stopped, until time t8, at which point theprocessed substrate has been completely transported to outside theprocessing chamber, this cover potential being selectable either asequivalent to the self-bias potential of the lower electrode 2300, or asa potential with the same polarity as and a larger absolute value thanthe above-noted self-bias potential. Particles that are generated in theperiod from the time immediately after the stopping of application ofthe high-frequency voltage to the time the transporting port opens arecollected by the cover, and therefore do not become attached to thesubstrate.

[0128] (Sixth Embodiment)

[0129] The flow of cover operation timing in the sixth embodiment of thepresent invention is shown in FIG. 8.

[0130] In the cases of the second and third embodiments of the presentinvention, as shown in FIG. 4 and FIG. 5, it is possible to impart apotential to the cover, from the time that the cover is started to beclosed until the time the cover is opened. By making the cover 3600 thesame potential as the lower processing electrode 2300 during theapplication of the high-frequency voltage, there is no discharge betweenthe substrate 3000 and the cover 3600, thereby enabling prevention ofdamage to the substrate and the generation of particles between thecover and the substrate.

[0131] Then, after the application of the high-frequency voltage isstopped, the cover potential is either made equivalent to the self-biaspotential, or a potential that has the same polarity as and an absolutevalue that is greater than the self-bias value.

[0132] It is also possible to apply this embodiment to the firstembodiment.

[0133] (Seventh Embodiment)

[0134]FIG. 10 shows one typical operating cycle of an etching apparatusgenerally used in a semiconductor device plant.

[0135] Etching is performed by introducing a highly reactive processinggas such as chlorine into the processing chamber from a spraying platethat also serves as the upper processing electrode that is in oppositionto the substrate and, when the pressure reaches a prescribed pressure,applying a voltage between the electrodes, so as to generate a plasma ofthe processing gas.

[0136] When etching is completed, the application of the high-frequencyvoltage and the introduction of the processing gas are stoppedsimultaneously and, after several seconds have elapsed, a purging gashaving a low reactivity, such as a halogen gas, is introduced.

[0137] In an etching apparatus of the seventh embodiment of the presentinvention, as shown in FIG. 11, the process gas supply is stopped whenthe etching is completed. When this is done, it is known that theparticles have a positive charge and, by making use of this phenomenon,by imparting a negative potential to an electrically conductiveparticle-removing electrode 11 that is provided between the upperprocessing electrode 2200 and lower processing electrode 2300 inside theprocessing chamber 2100, particles are forcibly removed. As long asthere is no influence on the process, the particle-removing electrode 11can be any shape such as that of a sheet or grid.

[0138] The large number of falling particles that are generated at theinstant that the high-frequency voltage is stopped are trapped by theparticle-removing electrode 11, thereby preventing their reaching thesubstrate 3000.

[0139] It is also possible to adopt a configuration in which a powersupply controller 420 and a negative power supply 410 are provided,whereby a negative potential is applied to the electrode 11 insynchronization with the completion of the etching.

[0140] (Eighth Embodiment)

[0141]FIG. 12 shows an etching apparatus into which a function has beenbuilt to trap particles, using an attachment-prevention shield.

[0142] In a semiconductor device manufacturing apparatus, anattachment-prevention shield 12 is often used to prevent the attachmentof sediments that occur during processing onto the chamber walls.

[0143] These attachment-prevention shields 12 are provided between theprocessing electrodes 2200, 2300 and the side walls of the processingchamber 2100, and intentionally cause sediments to be deposited ontothese attachment-prevention shields 12, and by replacing theattachment-prevention shields 12, it is possible to reduce the number oftimes the inside of the chamber needs to be cleaned.

[0144] The attachment-prevention shield 12 is often made of anelectrically conductive metal, the attachment-prevention shield 12 beingkept electrically insulated from the processing chamber, and when theetching is completed the supply of processing gas is stopped and anegative potential is imparted to the attachment-prevention shield 12.

[0145] The large number of positively charged falling particles that aregenerated at the instant that the high-frequency voltage is stopped arepulled in by the negative potential on the attachment-prevention shield12 and trapped and ultimately are trapped on the wall of theattachment-prevention shield 12, thereby preventing their reaching thesubstrate 3000.

[0146] (Ninth Embodiment)

[0147]FIG. 13 shows an etching apparatus into which a function has builtto trap particles, using an electrically conductive grid 13.

[0148] Specifically, the grid 13 is provided between the processingelectrodes 2200, 2300 and the side walls of the processing chamber 2100,this grid 13 being installed so that it is electrically insulated fromthe processing chamber and, when the etching is completed, the supply ofprocessing gas is stopped and a negative potential is imparted to thegrid 13.

[0149] The large number of positively charged particles that fall whenthe high-frequency voltage is stopped are pulled in by the negativepotential of the grid 13, and are ultimately trapped by this grid 13, sothat they are prevented from reaching the substrate.

[0150] (Tenth Embodiment)

[0151]FIG. 14 shows an etching apparatus in which a gas exhaust port 14at the bottom of the processing chamber is formed of an electricallyconductive material such as a metal, this gas exhaust port 14 beingelectrically insulated, so that particles are guided to the exhaust portand forcibly exhausted, the result being that the particles do not fallonto the substrate.

[0152] That is, when the supply of the processing gas is stopped at thecompletion of the etching, a negative potential is imparted to theexhaust port 14, the result being that the large number of positivelycharged particles that fall at the instant the high-frequency voltage isstopped are pulled in toward the exhaust port 14, which has a negativepotential, these particles being ultimately exhausted, so that they areprevented from reaching the substrate.

[0153] (Eleventh Embodiment)

[0154]FIG. 15 shows an etching apparatus in which an electricallyconductive grid 13 is provided in proximity to the gas exhaust port 14,this grid serving to trap particles.

[0155] Specifically, the grid 13 is installed in front of the exhaustport 14 so that it is electrically insulated with respect to thechamber, the supply of the processing gas being stopped and a negativepotential being imparted to the grid 13 when etching is completed.

[0156] The large number of positively charged particles that fall at theinstant the high-frequency voltage is stopped are pulled in toward thegrid 13 because of its negative potential, and are ultimately trapped bythe grid 13 or exhausted from the exhaust port 14, so that they areprevented from reaching the substrate.

[0157] (Twelfth Embodiment)

[0158]FIG. 16 shows the twelfth embodiment of the present invention.

[0159] In this embodiment, the electrically conductive grid 13 isinstalled between the upper electrode 2200 and the lower electrode 2300,and is placed in an electrically floating condition. By doing this,during the process, that is during discharge, the grid 13 tracks to thepotential of the plasma, so that it is in the floating condition.

[0160] After the process is completed, when a negative potential isimparted to the grid 13, particles are pulled in toward the negativepotential of the grid 13, thereby being prevented from reaching thesubstrate. Then, in this condition, the semiconductor substrate 3000 istransported.

[0161] (Thirteenth Embodiment)

[0162]FIG. 17 shows the thirteenth embodiment of the present invention.

[0163] In this embodiment, a plasma PZ is generated that is sufficientlylarge with respect to the semiconductor substrate 3000. This plasma PZis generated in accordance with the diameters of the upper electrode2200 and the lower electrode 2300 and, in the case of FIG. 17, this is aplasma that is generated to considerably outside the substrate 3000.

[0164] By doing this, so that the plasma PZ extends greatly beyond thesubstrate 3000, particles drop along the outer periphery of the plasmaPZ, thereby preventing them from falling onto the substrate 3000.

[0165] (Fourteenth Embodiment)

[0166]FIG. 18 shows the fourteenth embodiment of the present invention.

[0167] In this embodiment, a donut-shaped electrode 15 is installed overthe lower electrode 2300 so as to surround the substrate 3000, anegative voltage that has an absolute value that is greater than theself-bias voltage being applied to the electrode 15, in which case theapplied voltage can be a DC voltage.

[0168] The timing of the application of the above-noted voltage is thetime that the process is completed and the time that the plasma powersupply is turned off.

[0169] A negative bias is applied with respect to the voltage applied tothe lower electrode 2300, which is the cathode electrode, and this iscaused to vary in the same manner as the self-bias voltage.

[0170] By doing the above, positively charged particles are guided tothe electrode 15, thereby preventing them from falling onto thesubstrate 3000.

[0171] (Fifteenth Embodiment)

[0172]FIG. 19 shows the fifteenth embodiment of the present invention.

[0173] In this embodiment, a laser apparatus is introduced for thepurpose of monitoring the generation of particles. The location at whichthe laser light is shined is the region under the anode electrode, thisbeing the upper electrode 2200. By adopting this configuration, it ispossible to detect particles at an early stage that are trapped in theregion near the plasma sheath.

[0174] Then, after the particles are detected, a negative voltage isapplied to the electrode 15, so as to collect the particles, preventingthem from falling onto the substrate 3000.

[0175] (Sixteenth Embodiment)

[0176]FIG. 20 shows the sixteenth embodiment of the present invention.

[0177] In this embodiment, a particle-removing electrode 15 is providedbetween the upper electrode 2200 and the lower electrode 2300, and agate valve 17 is installed on a side wall of the processing chamber nearthe particle-removing electrode 15, a vacuum pump or other suchexhausting apparatus being connected to the outside thereof. A provisionis also made to apply a negative voltage to the electrode 15.

[0178] When the processing is completed and the voltage applied to thecathode electrode, which is the lower electrode 2300, is cut off, anegative voltage is applied to the electrode 15. By doing this,particles are pulled toward the gate valve 17. When this occurs, thegate valve 17 is simultaneously opened, so that the particles areexhausted, thereby preventing the particle from falling onto thesubstrate 3000.

[0179] In FIG. 19, the reference numeral 450 denotes a third controlmeans for the purpose of applying a negative voltage to theparticle-removing electrode 15, based on the results of the detection ofparticles within the processing chamber.

[0180] All of the above-described first embodiment through sixteenthembodiment can be applied in common to an RF plasma CVD apparatus, an RFplasma etching apparatus, and an RF plasma sputtering apparatus.

[0181] In contrast to the above, the seventeenth through thirty-secondembodiments to be described below can be applied in common to a DCplasma CVD apparatus, a DC plasma etching apparatus, and a DC plasmasputtering apparatus.

[0182] (Seventeenth Embodiment)

[0183] The flow of cover operation timing in the seventeenth embodimentof the present invention is shown in FIG. 22.

[0184] At the time t11, immediately before the stopping of the DCvoltage, the cover 3600 that covers the substrate 3000 is closed and, atthe instant that the DC voltage is stopped, particles that fall towardthe substrate 3000 are caught by the cover 3600. The cover 3600 remainsclosed during the introduction of the purging gas, at which time thereis a high frequency of generation of particles and, after theintroduction of the purging gas is stopped, at the time t12, immediatelybefore the processed substrate is transported to outside the processingchamber 2100, the cover is opened. Thus, during the period of time whenmany particles P would fall onto the substrate, because the cover 3600is in the closed condition, thereby reliably covering the substrate3000, the attachment of the particles P onto the substrate 3000 isprevented.

[0185] The shape of the cover can be that of a single sheet, or that ofa plurality of blades, such as those of a camera shutter.

[0186] (Eighteenth Embodiment)

[0187] The flow of cover operation timing in the eighteenth embodimentof the present invention is shown in FIG. 23.

[0188] At the time t11, immediately before the stopping of the DCvoltage, the cover 3600 that covers the substrate 3000 is closed and, atthe instant that the DC voltage is stopped, particles that fall towardthe substrate 3000 are caught by the cover 3600. After the processedsubstrate 3000 is transported to outside the processing chamber 2100, atthe time t13, immediately before the next substrate is transported intothe processing chamber, the cover 3600 is opened. Thus, by operating thecover in this manner, attachment of particles that fall onto thesubstrate is prevented.

[0189] (Nineteenth Embodiment)

[0190] The flow of cover operation timing in the nineteenth embodimentof the present invention is shown in FIG. 24.

[0191] At the time t14, immediately before the application of the DCvoltage, the cover that covers the substrate 3000 is opened and, at timet11, immediately before the DC voltage is stopped, the cover is closed.By closing the cover when etching is not being performed, particlesoccurring because of peeling from the upper electrode 2200 or from theinside walls of the processing chamber 2000 are caught by the cover,thereby preventing the attachment of these particles to the substrate.

[0192] Furthermore, in addition to the above-noted configurations, it ispossible to use a configuration in which a detection means is providedthat detects that the cover 3600 has been placed in the closedcondition, the result of the detection by this detection means beingused to turn off the DC power supply 2400.

[0193] (Twentieth Embodiment)

[0194] The flow of cover operation timing in the twentieth embodiment ofthe present invention is shown in FIG. 25.

[0195] In addition to the seventeenth to the nineteenth embodiments,during the period of time from t15, immediately before the stopping ofthe application of the DC voltage, to the time t16, several secondsafter the start of the introduction of the purging gas, a potential isimparted to the cover 3600. Particles that are generated immediatelyafter the stopping of application of the DC voltage fall toward and areattracted to the cover 3600. Particles that are generated after theintroduction of the purging gas follow the flow of the purging gas, andfall toward the exhaust port, so that they do not become attached to thesubstrate.

[0196] The material of the cover 3600 can be the same conductivematerial as the processing chamber 2100 inner wall, this being forexample an aluminum alloy and, to reduce the number of particles thatare generated, it can also have a metallic surface that is covered withaluminum oxide or silicon oxide.

[0197] (Twenty-first Embodiment)

[0198] The flow of cover operation timing in the twenty-first embodimentof the present invention is shown in FIG. 26.

[0199] In the cases of the eighteenth and nineteenth embodiments of thepresent invention, as shown in FIG. 23 and FIG. 24, it is possible toimpart a potential to the cover from the time t17, at which theapplication of the DC voltage is stopped, until time t18, at which pointthe processed substrate has been completely transported to outside theprocessing chamber. Particles that are generated in the period from thetime immediately after the stopping of application of the DC voltage tothe time the transporting port opens are collected by the cover, andtherefore do not become attached to the substrate.

[0200] (Twenty-second Embodiment)

[0201] The flow of cover operation timing in the twenty-secondembodiment of the present invention is shown in FIG. 27.

[0202] In the cases of the eighteenth and nineteenth embodiments of thepresent invention, as shown in FIG. 23 and FIG. 24, it is possible toimpart a potential to the cover, from the time that the cover is startedto be closed until the time the cover is opened. By making the cover3600 the same potential as the lower processing electrode 2300 duringthe application of the DC voltage, there is no discharge between thesubstrate 3000 and the cover 3600, thereby enabling prevention of damageto the substrate and the generation of particles between the cover andthe substrate.

[0203] Then, after the application of the DC voltage is stopped, thecover potential is either made equivalent to the self-bias potential, ora potential that has the same polarity as and an absolute value that isgreater than the self-bias value.

[0204] It is also possible to apply this embodiment to the seventeenthembodiment.

[0205] (Twenty-third Embodiment)

[0206]FIG. 28 shows one typical operating cycle of a DC plasmaprocessing apparatus generally used in a semiconductor device plant.

[0207] In the twenty-third embodiment of a DC plasma processingapparatus shown in FIG. 29, when the DC plasma processing is completed,it is known that the particles have a positive charge and, by making useof this phenomenon, by imparting a negative potential to an electricallyconductive particle-removing electrode 11, particles are removed. Aslong as there is no influence on the DC plasma process, theparticle-removing electrode 11 can be any shape such as that of a sheetor grid.

[0208] The large number of falling particles that are generated at theinstant that the DC voltage is stopped are trapped by theparticle-removing electrode 11, thereby preventing their reaching thesubstrate 3000.

[0209] (Twenty-fourth Embodiment)

[0210]FIG. 30 shows a DC etching apparatus into which a function hasbeen built to trap particles, using an attachment-prevention shield.

[0211] In a semiconductor device manufacturing apparatus, anattachment-prevention shield 12 is often used to prevent the attachmentof sediments that occur during processing onto the chamber walls.

[0212] These attachment-prevention shields intentionally cause sedimentsto be deposited onto these attachment-prevention shields 12, and byreplacing the attachment-prevention shields 12, it is possible to reducethe number of times the inside of the chamber needs to be cleaned.

[0213] The attachment-prevention shield 12 is often made of anelectrically conductive metal, the attachment-prevention shield 12 beingkept electrically insulated from the processing chamber, and when theetching is completed, a negative potential is imparted to theattachment-prevention shield 12.

[0214] The large number of positively charged falling particles that aregenerated at the instant that the DC voltage is stopped are pulled in bythe negative potential on the attachment-prevention shield 12 andtrapped and ultimately are trapped on the wall of theattachment-prevention shield 12, thereby preventing their reaching thesubstrate 3000.

[0215] (Twenty-fifth Embodiment)

[0216]FIG. 31 shows an etching apparatus into which a function has builtto trap particles, using an electrically conductive grid 13.

[0217] Specifically, the grid 13 is installed so that it is electricallyinsulated from the processing chamber and, when the etching iscompleted, a negative potential is imparted to the grid 13.

[0218] The large number of positively charged particles that fall whenthe DC voltage is stopped are pulled in by the negative potential of thegrid 13, and are ultimately trapped by this grid 13, so that they areprevented from reaching the substrate.

[0219] (Twenty-sixth Embodiment)

[0220]FIG. 32 shows a DC plasma processing apparatus in which a gasexhaust port 14 is formed at the bottom of the processing chamber and iselectrically insulated from the chamber, thereby forcibly exhaustingparticles.

[0221] That is, in the above-noted particle-removing apparatus, when theDC plasma processing is completed, a negative potential is imparted tothe exhaust port 14, the result being that the large number ofpositively charged particles that fall at the instant the DC voltage isstopped are pulled intoward the exhaust port 14, which has a negativepotential, these particles being ultimately exhausted, so that they areprevented from reaching the substrate 3000.

[0222] (Twenty-seventh Embodiment)

[0223]FIG. 33 shows an etching apparatus in which an electricallyconductive grid 13 is provided in proximity to the gas exhaust port 14,this grid serving to trap particles.

[0224] Specifically, the grid 13 is installed in front of the exhaustport 14 so that it is electrically insulated with respect to thechamber, a negative potential being imparted to the grid 13 when DCplasma processing is completed.

[0225] The large number of positively charged particles that fall at theinstant the DC voltage is stopped are pulled in toward the grid 13because of its negative potential, and are ultimately trapped by thegrid 13 or exhausted from the exhaust port 14, so that they areprevented from reaching the substrate 3000.

[0226] (Twenty-eighth Embodiment)

[0227]FIG. 34 shows the twenty-eighth embodiment of the presentinvention.

[0228] In this embodiment, the electrically conductive grid 13 isinstalled between the upper electrode 2200 and the lower electrode 2300,and is placed in an electrically floating condition. By doing this,during the process, that is during discharge, the grid 13 tracks to thepotential of the plasma, so that it is in the floating condition.

[0229] After the process is completed, the grid 13 is connected to apower supply 4400, and a discharge is caused between the grid 13 and theupper electrode 2200. When this is done, the power supply 4400 is notconnected to the lower electrode 2300.

[0230] Then, in this condition, the semiconductor substrate 3000 istransported. By doing this, particles remain trapped between the upperelectrode 2200 and the grid 13 and fly toward the area surrounding theplasma where they fall around the periphery thereof, so that they do notfall onto the substrate.

[0231] (Twenty-ninth Embodiment)

[0232]FIG. 35 shows the twenty-ninth embodiment of the presentinvention.

[0233] In this embodiment, a plasma PZ is generated that is sufficientlylarge with respect to the semiconductor substrate 3000. This plasma PZis generated in accordance with the diameters of the upper electrode2200 and the lower electrode 2300 and, in the case of FIG. 35, this is aplasma that is generated to considerably outside the substrate 3000.

[0234] By doing this, so that the plasma PZ extends greatly beyond thesubstrate 3000, particles drop along the outer periphery of the plasmaPZ, thereby preventing them from falling onto the substrate 3000.

[0235] (Thirtieth Embodiment)

[0236]FIG. 36 shows the thirtieth embodiment of the present invention.

[0237] In this embodiment, a donut-shaped electrode 15 is installed overthe lower electrode 2300 so as to surround the substrate 3000, anegative voltage being applied to the electrode 15.

[0238] The timing of the application of the above-noted voltage is thetime that the process is completed and the time that the plasma powersupply is turned off.

[0239] By doing the above, positively charged particles are guided tothe electrode 15, thereby preventing them from falling onto thesubstrate 3000.

[0240] (Thirty-first Embodiment)

[0241]FIG. 37 shows the thirty-first embodiment of the presentinvention.

[0242] In this embodiment, a laser apparatus is introduced for thepurpose of monitoring the generation of particles. The location at whichthe laser light is shined is the region under the upper electrode 2200.By adopting this configuration, it is possible to detect at an earlystage particles that are trapped in the region near the plasma sheath.

[0243] Then, after the particles are detected, a negative voltage isapplied to the electrode 15, so as to collect the particles, preventingthem from falling onto the substrate 3000.

[0244] (Thirty-second Embodiment)

[0245]FIG. 38 shows the thirty-second embodiment of the presentinvention.

[0246] In this embodiment, gate valves 17 are installed on the side wallof the processing chamber near the upper electrode 2200, a vacuum pumpor other such exhausting apparatus being connected to the outsidethereof. An electrode 15 is installed in front of the gate valve 17, anda provision is also made to apply a negative voltage to this electrode15.

[0247] When the processing is completed and the voltage applied to thelower electrode 2300, is cut off, a negative voltage is applied to theelectrode 15. By doing this, particles are pulled toward the gate valve17. When this occurs, the gate valve 17 is opened, so that the particlesare exhausted, thereby preventing the particle from falling onto thesubstrate 3000.

[0248] As described in detail above, the present invention is capable ofreducing the particles that become attached to a substrate, and is aninvention that is based on the charged condition of the particles,enabling highly efficient prevention of attachment of particles.

What is claimed is:
 1. A particle-removing apparatus in a semiconductordevice manufacturing apparatus in which a high-frequency voltage isapplied between an upper electrode and a lower electrode so as togenerate a plasma within a processing chamber that processes a substratelocated in said processing chamber, in which is provided a cover thatcovers said substrate, said substrate being covered by closing saidcover, so as to prevent the attachment of particles within saidprocessing chamber to said substrate, wherein said particle-removingapparatus comprising a first control means for controlling the timing ofdrive of said cover, said control means performing control so as tochange said cover from an opened condition to a closed conditionimmediately before stopping the application of said high-frequencyvoltage.
 2. A particle-removing apparatus according to claim 1, whereincontrol is performed so that said cover is changed from the closedcondition to the open condition in synchronization with a transportoperation of a substrate-transporting apparatus provided in saidsemiconductor device manufacturing apparatus.
 3. A particle-removingapparatus according to claim 2, wherein the timing of the control of thechange of said cover from the closed condition to the opened conditionis immediately before a processed substrate is transported to outsidesaid processing chamber.
 4. A particle-removing apparatus according toclaim 2, wherein the timing of the control of the change of said coverfrom the closed condition to the opened condition is immediately aftersaid substrate is transported to outside said processing chamber.
 5. Aparticle-removing apparatus according to claim 1, wherein the timing ofthe control of the change of said cover from the closed condition to theopened condition is immediately before application of saidhigh-frequency voltage.
 6. A particle-removing apparatus according toclaim 1, wherein a potential is imparted to said cover, saidparticle-removing apparatus further comprising a second control meanswhich performs control of the timing of imparting said potential to saidcover, and said control means performing control so that the potentialis imparted to the cover minimally from immediately before the stoppingof application of the high-frequency voltage to several seconds afterthe starting of introduction of a purging gas.
 7. A particle-removingapparatus according to claim 1, wherein a potential is imparted to saidcover, said particle-removing apparatus further comprising a secondcontrol means which performs control of the timing of imparting saidpotential to said cover, and said control means performing control sothat the potential is imparted to the cover minimally from immediatelybefore the stopping of application of the high-frequency voltage untilimmediately before said purging gas is introduced.
 8. Aparticle-removing apparatus according to claim 6, wherein said potentialis imparted until the time at which said substrate is transported tooutside said processing chamber.
 9. A particle-removing apparatusaccording to claim 6, wherein said potential is selected from a groupconsisting of a voltage that is equivalent to a self-bias voltage thatappears on said lower electrode and a voltage that has the same polarityas said self-bias voltage and an absolute value that is larger than saidself-bias voltage.
 10. A particle-removing apparatus according to claim6, wherein said potential is equivalent to the potential on said lowerelectrode.
 11. A particle-removing method in a semiconductor devicemanufacturing apparatus in which a high-frequency voltage is applied soas to generate a plasma within a processing chamber that processes asubstrate located in said processing chamber, in which is provided acover that covers said substrate, said substrate being covered byclosing said cover, so as to prevent the attachment of particles withinsaid processing chamber to said substrate, wherein saidparticle-removing method comprising a first step of controlling saidcover from the opened condition to the closed condition immediatelybefore stopping the application of said high-frequency voltage.
 12. Aparticle-removing method according to claim 11, further comprising asecond step of controlling said cover so as to change from said closedcondition to said open condition in synchronization with a transportoperation of a substrate transporting apparatus that is provided in saidsemiconductor device manufacturing apparatus.
 13. A particle-removingmethod in a semiconductor device manufacturing apparatus in which ahigh-frequency voltage is applied so as to generate a plasma within aprocessing chamber that processes a substrate located in said processingchamber, in which is provided a cover that covers said substrate, saidsubstrate being covered by closing said cover, so as to prevent theattachment of particles within said processing chamber to saidsubstrate, said particle-removing method comprising: a first step ofchanging said cover from the opened condition to the closed condition; asecond step of stopping the application of said high-frequency voltageimmediately after said cover is placed in the closed condition; and athird step of imparting a potential to said cover.
 14. Aparticle-removing apparatus of a semiconductor device manufacturingapparatus that comprises an etching processing chamber, a pair ofprocessing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, a processing gas being introduced into said etchingprocessing chamber, a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, and a particle-removingelectrode for the purpose of removing particles being provided insidesaid processing chamber, whereby, after completion etching of saidsubstrate, a negative voltage is applied to said particle-removingelectrode, so that charged particles inside said processing chamber areguided to said particle-removing electrode and caused to be attachedthereto, thereby removing said particles.
 15. A particle-removingapparatus according to claim 14, wherein said particle-removingelectrode is provided between said upper electrode and said lowerelectrode.
 16. A particle-removing apparatus according to claim 14,further comprising an exhaust port disposed on a side wall of saidetching chamber, in a region in which said particle-removing electrodeis provided.
 17. A particle-removing apparatus according to claim 14,wherein said particle-removing electrode is provided above said lowerelectrode in a manner that surrounds said substrate.
 18. Aparticle-removing apparatus according to claim 14, wherein saidparticle-removing electrode is provided between said processingelectrode and a side wall of said processing chamber.
 19. Aparticle-removing apparatus according to claim 18, wherein saidparticle-removing electrode is a attachment-preventing plate thatprevents sediments from becoming attached to a wall surface of saidprocessing chamber.
 20. A particle-removing apparatus according to claim14, wherein said particle-removing electrode is provided within a gasexhaust port or said etching processing chamber or near said exhaustport.
 21. A particle-removing apparatus of a semiconductor devicemanufacturing apparatus that comprises an etching processing chamber, apair of processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, wherein a processing gas being introduced into saidetching processing chamber, and a prescribed voltage being applied tosaid processing electrodes, so as to generate a plasma of said gas,thereby processing the substrate on the susceptor, saidparticle-removing apparatus comprising a gas exhaust port of saidprocessing chamber, which is formed of an electrically conductivematerial, a negative voltage being applied to said electricallyconductive material, so as to remove charged particles within saidprocessing chamber.
 22. A particle-removing apparatus of a semiconductordevice manufacturing apparatus that comprises an etching processingchamber, a pair of processing electrodes formed by an upper electrodeand a lower electrode, which are installed within said processingchamber, and a susceptor that holds a substrate to be processed onto thetop of said lower electrode, wherein a processing gas being introducedinto said etching processing chamber, and a prescribed voltage beingapplied to said processing electrodes, so as to generate a plasma ofsaid gas, thereby processing the substrate on the susceptor, saidparticle-removing apparatus comprising an electrically conductivegrid-configured material for the purpose of particle removed, saidmaterial being disposed between said upper electrode and said lowerelectrode, and a negative voltage being applied to said grid-configuredmaterial, so as to remove charged particles from said processingchamber.
 23. A particle-removing apparatus of a semiconductor devicemanufacturing apparatus that comprises an etching processing chamber, apair of processing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, a processing gas being introduced into said etchingprocessing chamber, and a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, said particle-removingapparatus comprising a particle-removing electrode for the purpose ofremoving particles, said particle-removing electrode being disposed aregion near said substrate, a negative voltage that has an absolutevalue that is larger than a self-bias voltage of said lower electrodebeing applied thereto, so as to prevent particles within said processingchamber from falling onto said substrate.
 24. A particle-removingapparatus of a semiconductor device manufacturing apparatus thatcomprises an etching processing chamber, a pair of processing electrodesformed by an upper electrode and a lower electrode, which are installedwithin said processing chamber, and a susceptor that holds a substrateto be processed onto the top of said lower electrode, a processing gasbeing introduced into said etching processing chamber, and a prescribedvoltage being applied to said processing electrodes, so as to generate aplasma of said gas, thereby processing the substrate on the susceptor, aconstant bias being applied to said lower electrode, said bias beingcaused to vary in the same manner as said self-bias voltage, so as tocause charged particles to be directed toward said lower electrode,thereby preventing said particles from falling onto said substrate. 25.A particle-removing apparatus according to any one of claim 14 throughclaim 24, further comprising a laser apparatus for the purpose ofdetecting the generation of said particles, light from said laserapparatus being shined in a region near said upper electrode, andcomprising a third control means for the purpose of applying a negativevoltage to said particle-removing electrode, based on the results ofsaid detection.
 26. A particle-removing apparatus according to claim 14,wherein said particle-removing electrode is electrically conductive andplanar in configuration.
 27. A particle-removing apparatus according toclaim 14, wherein said particle-removing electrode is an electricallyconductive grid-configured electrode.
 28. A particle-removing apparatusaccording to claim 14, wherein said negative voltage is applied aftercompletion of etching.
 29. A particle-removing apparatus according toclaim 14, wherein said negative voltage is applied during transportingof said substrate.
 30. A particle-removing method for a semiconductordevice manufacturing apparatus that comprises an etching processingchamber, a pair of processing electrodes formed by an upper electrodeand a lower electrode, which are installed within said processingchamber, and a susceptor that holds a substrate to be processed onto thetop of said lower electrode, a processing gas being introduced into saidetching processing chamber, and a prescribed voltage being applied tosaid processing electrodes, so as to generate a plasma of said gas,thereby processing the substrate on the susceptor, a particle-removingelectrode being provided for the purpose of removal of particles in saidprocessing chamber, said method applying a negative voltage to saidparticle-removing electrode after completion of etching of saidsubstrate, so as to guide charged particles inside said processingchamber to said particle-removing electrode, thereby preventing saidparticles from becoming attached to said substrate.
 31. Aparticle-removing method according to claim 29, whereby, afterapplication of a negative voltage to said particle-removing electrode,said etching gas is exhausted from within said processing chamber.
 32. Aparticle-removing method for a semiconductor device manufacturingapparatus that comprises an etching processing chamber, a pair ofprocessing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, a processing gas being introduced into said etchingprocessing chamber, and a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, an electrode being providedwithin a gas exhaust port or in proximity of said gas exhaust port ofsaid processing chamber for the purpose of removing particles, saidmethod applying a negative voltage to said electrode, so as to guidecharged particles toward said gas exhaust port and simultaneouslyexhaust etching gas from said processing chamber.
 33. Aparticle-removing method for a semiconductor device manufacturingapparatus that comprises an etching processing chamber, a pair ofprocessing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, a processing gas being introduced into said etchingprocessing chamber, and a prescribed voltage being applied to saidprocessing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, a gas exhaust port of saidprocessing chamber being formed of an electrically conductive material,said method applying a negative voltage to said exhaust port, so as toguide charged particles toward said exhaust port, and simultaneouslyexhaust etching gas from said processing chamber.
 34. Aparticle-removing method for a semiconductor device manufacturingapparatus that comprises an etching processing chamber, a pair ofprocessing electrodes formed by an upper electrode and a lowerelectrode, which are installed within said processing chamber, and asusceptor that holds a substrate to be processed onto the top of saidlower electrode, a processing gas being introduced into said etchingprocessing chamber, and a prescribed voltage being applied to said+*processing electrodes, so as to generate a plasma of said gas, therebyprocessing the substrate on the susceptor, said method forming a plasmahaving a size that extends greatly beyond said substrate, so thatparticles within said processing chamber fall along the outer peripheryof said plasma, thereby being prevented from becoming attached to saidsubstrate.